Facebook has been targeting teens who feel "worthless" and "insecure" through customized advertising campaigns, according to the Australian on Monday. The teens are as young as 14, and the social media network identifies their emotional state by monitoring photos, posts and online activity in real-time.

Detailed in a 23-page report marked "Confidential: Internal Only," Facebook can assess when young people feel "overwhelmed," "nervous," "stupid," "useless, "defeated" and more. It then passes the data onto third-party marketing companies.

According to the site's policy, its advertisers have agreed to "expand their public knowledge centers so that anyone can learn how they collect and use information."

"This includes clearly explaining what types of information they collect and what their policies are relating to the sharing of that information," Facebook explained.

What exactly this means remains unclear, and some believe the sponsored ads are an invasion of privacy.

More than 6 million "young Australians and New Zealanders...in the workforce," "high schoolers" and "tertiary students" were surveilled, according to the documents, which were reportedly prepared by Australian Facebook executives Andy Sinn and David Fernandez.

“We have opened an investigation to understand the process failure and improve our oversight," the company said in a statement. "We will undertake disciplinary and other processes as appropriate."

The news comes months after the social media network said it reached nearly 2 billion users - roughly a quarter of the world's population.

In 2014, the company revealed it had altered the news feeds of more than half a million randomly chosen users in an experiment that analyzed how emotions spread online. After receiving some backlash, Facebook claimed its actions were covered in its terms of service.

A February survey showed that more Americans are growing concerned over their lack of digital privacy.

Eight of 10 people don't like that they're being digitally tracked by third parties, according to research from Envista Forensics, an Atlanta-based technology and forensic engineering firm. Seventy-one percent of people are more concerned about online privacy then they were a decade ago.

"At this point, the idea of sharing your personal information with a company is no longer novelty but the norm — it’s a given to use the phone, the app, the social media platform, the streaming service, the latest game," Envista Forensics said. "However, as we discovered in our recent survey, the kind of data being collected and what it’s being used for is far from what the average person assumes when they click 'YES' to the fine print."